Theres my dyno graph from yesterday. At about 6K rpm, my ignition was misfiring like crazy. It was bad enough that the tach on the dyno wasnt working(thats why its in mph). I suspect it was my Crane Hi-6, and that is coming off today.

100 mph is at 5867 RPM, and right after that, around 6K, is where the misfiring starts, and the graph takes a dive.

 

well the dyno tach was probably hooked up to your trailing (other wise it would be at 12000rpm) and the hi-6 would be on your leading. so I don't think that would be your problem.

 

They had the dyno tach set up right for rotaries, none of the other rotaries had tach problems. What was causiung the misfiring on my car, I dont know for sure yet, but I am going to start diagnosing it working on it. I think the Crane Hi-6 isnt helping any, at best.

 

hmmm.. I don't mean to rain on your parade or anything.. any this doesn't really have much to do with your ignition breakup, but 127 rwhp is quite disapointing for a 1990 n/a .. hell even given a 15% driveline loss, you're still makeing near stock power.. even without that sharp drop off at 6000 rpm I doubt your max power would have increased by more then 10 hp...
Actually it's kinda nice that you posted some proof of what your car is doing..since prior to this all I have heard was "I'll beat a slightly modded T2" .. musta been some pretty sick t2 then..

With all the talk about porting intake manifolds, wiring open your MAF doors etc, this should wake some people up to realize, you arn't going to be making free power.. power costs money .. If you arn't willnig to do it right the first time, you're just gonna be saddened when you get yourself to the dyno and find out you've made squat, and in some cases, even loss power...

sorry, don't take what i said too harshly.. I'm being a bitch today..

 

Hey man, don't rain on the parade yet. TII makes power from 3000 rpm and ends around 6.5k rpm. NA don't make power until around 5500rpm and up to 7500rpm, so we havent't began to see the powerband yet. And that is stock. With his mods, he should be making power from 6-7k rpm all the way up to 8.5k rpm.

Have some faith man.
Don't let us down Mazdaspeed7

Later

 

Lucky for you I didn't have my car together then

 

Honestly guys IMHO the N/A's are good for about 145 - 165 rwhp max. (Unless you do a ton of porting and stuff). I suspect that Adam will run ~150 rwhp once he gets his problems sorted out. If you want more power than mid 100's... you're best bet is to get a TII.

 

Well, I am ditching my MSD- but it is because I get **** on after 8000 RPM's (A tiny bit of hestiation first at around 7000, then hits a wall at 8000) Without it- the rev was smooth up to 9K.
I'm supprised it would start messing up at only 6000.

Havn't you mentioned that you were running lean? Did they check that with a wideband at the dyno? If not- you should check the voltage off you o2 sensor when you're driving.

With your dual's and such, it sucks that you are losing the best part of you power curve. (up high!)

Another thought, but I'm pretty dumb- It's not possible that you
accidentally had the VDI set in low range is it?

OK- also- the topic of this post isn't about the difference in power between N/A and turbo- I don't think anyone will argue that a turbo makes more power, but you can get an N/A up to pretty good speed, and they are much simpler and more reliable than turbos- not to mention- No lag! It's all motor- all the time. Some people prefer it, I know I do. I'm not in denial, thinking my car is the fastest out there- If I want a drag car, I would get a Mustang or something., Now please, lets drop this tired debate, get back on topic, and discuss the intended technical problem in this thread.

Mazdaspeed7- Let's here what happens when you remove the Hi-6.

 

Don't let us down Adam. Get everything sorted out, and get back to the dyno. You know, and i was just thinking about getting a HI-6. Maybe i won't CJ

 

It also looks like to me, that if the graph would of kept going the way it was going....the motor should of made atleast 150rwhp...but this is just a guess. But overall the power curve (what is there) does have a nice ramp to it. CJ

 

yeah, no lag...but you still gotta rev the **** outta n/a's to start gaining speed ...don't people LOSE low end torque with a street port? but gain in the upper rpms....

 

Hmmmmmmmm, wanna race?

Just kidding, hope you fix that soon.

 

A little more info on my car, so you can see just how disappointing this was. My car has a nicely increasing torque curve, from 2K rpm up. It starts making good power around 4K-4500. At 6K rpm, the torque spikes, and the tach needle starts moving towards the rev limiter at 8800 very quickly. My real power is from 6K to the rev limiter, and that is the part of the dyno that is missing due to the ignition misfires.

Bambam7, I got the Crane off, but my timing needs to be reset. Ill let you know later how it all turns out.

 

Another question- Does your car feel like it drives fine? Good power??
I am guessing that this problem just happened recently, because there is NO WAY that 130 hp can push an RX-7 the a low 14sec 1/4, and 140 mph top speed.
Did it only do this on the dyno or something?

 

I seriously doubt that your torque "spikes" at 6k rpm. Typically the torque will slowly drop from 3000 as HP increases. Your car is probably good for 145 - 155 when running perfectly. No offense, just don't expect any more than that... if you NEED more you'll probably need to do something with the motor.

Also the dyno's tach was messed up, he had to do EVERYONE's car by speed rather than rpms. I know for a fact that Tim Benton's car puts out a good tach signal, and they couldn't even get a good signal on his car.

You may want to look at your fuel, I'm not sure that you need the 550cc injectors or the FD pump. Carls car seems to do best with the stock injectors, and he has never had a detonation problem with his. Also his has aftermarket mufflers so I would suspect that his would probably flow better and need the fuel more than yours.

Take care,

 

Isn't Carl's the one that did 138.8 last year? I've been off the SERX7 list too long

 

Yeah... it has no lag... it just lags the WHOLE TIME!!

Just joking around, don't take offense. I love N/A's just the same as TII's... I still miss my N/A.

 

It may have done 138.8 last year, but these days his car runs consistant low 150's @ the wheels, with a nice power band and all. Basically IMHO Carl's car is what most of the N/A's on here should aspire to be power wise. There isn't much left that Carl can do besides porting his motor.

 

I drove 3 1/2 hours from Sav to Atl on Friday night, noticed my car was feeling sluggish on the top, especially. Sat morning, same thing, dyno was the worst I have ever seen my top end. I mean I had NO power, as you can see from the dyno chart. I drove 3 1/2 hours back to Sav, and the car seemed almost normal. I really dont have a clue.

I took the Hi-6 off tonight, and it got worse. I think the Hi-6 fucked my timing up royally. I am going to check it, and set it right on Tue at his shop. Im thinking I might have a bad coil or ignitor too, and Ill be checking that tomorrow.

 

https://www.rx7club.com/forum/showth...threadid=46740

Go read that, it explains some of the circumstances, that im sure didnt help me at the dyno. But yes, my ignition system is still messed up, hopefully I will have it fixed soon.

 

well considering an 89-91 N/A makes peak power at 7,000rpm STOCK, he is putting almost stock numbers out at 6,000rpm, since his power peak is around 8,500rpm i believe it would be around 170-180rwhp and maybe more, but i dont know.

 

I'll believe THAT when I see it. I've yet to ever see a stock ported N/A put out anything remotly near that. Someone please post a dyno sheet and prove me wrong...

Also Carl's car is running the 89 - 91 intake and manifold with working VDI and RPM actuated 6 ports.

 

You know Im coming back when I get my car sorted out. We've got some business to finish, since it was raining all weekend and all. Ill make sure my car is running right next time though. I might have the engine ported by then too. I AM going for a street port very soon. Probably before I dyno again. And Ill be coming to whoop up on some turbo's.

 

Agent_d: How do you know his peak power is up at 8500 rpm? Just because someone drives a motor to higher rpm levels then normal does not mean that power has dropped off from it's peak at a lower rpm...I have never seen any dyno numbers from any na's putting down more then 150hp without any porting done to the motor.. I highly doubt you wil ever see 180 hp from a stock motor..


mazdaspeed7: I'm also curious as to how you can equate the crane ignition to messing around with the timing.. the crane was removed and it's apperently gotten worse, and you state it somehow messed around with your ignition timing.. unless you yourself decided to start playing around with your base timing and played around with the CAS, how can you blame the crane for messing it up, especially since it's no longer in the circuit?

 

well lets see, stock power is at 7k rpm, now when you add an exhaust that has almost no backpressure your peak power is going to rise maybe 500 or so rpm, so say 7500 rpm, then his ported intake manifold, HELLA PORTED intake manifold should raise it another 500rpm, so lets say 8k, then with his UD pulley, e-fan, and other mods his peak power will be between 8-8500rpm.

man you turbo guys love to dis on us n/a boys